Galectin-1 is implicated in the protein kinase C epsilon/vimentin-controlled trafficking of integrin-beta1 in glioblastoma cells.
Cell motility and resistance to apoptosis characterize glioblastoma (GBM) growth and malignancy. In our current work we report that galectin-1, a homodimeric adhesion molecule and carbohydrate-binding protein with affinity for beta-galactosides, is linked with cell surface expression of integrin beta1 and the process of integrin trafficking. Using immunofluorescence, depletion of galectin-1 through both stable knockdown and transient-targeted small interfering RNA (siRNA) treatment induces an intracellular accumulation of integrin-beta1 coincident with a diminution of integrin-beta1 at points of cellular adhesion at the cell membrane. Galectin-1 depletion does not alter the gene expression level of integrin-beta1. Transient galectin-1 depletion effectuates as well the perinuclear accumulation of protein kinase C epsilon (PKCepsilon) and the intermediate filament vimentin, both of which have been shown to mediate integrin recycling in motile cells. Our results argue for the involvement of galectin-1 in the PKCepsilon/vimentin-controlled trafficking of integrin-beta1. The understanding of molecular mediators such as galectin-1 and the pathways through which they drive the cell invasion so descriptive of GBM is anticipated to reveal potential therapeutic targets that promote glioma malignancy.
Fortin
Shannon
S
Laboratory of Toxicology, Institute of Pharmacy, Univesité Libre de Bruxelles, Brussels.
Le Mercier
Marie
M
Camby
Isabelle
I
Spiegl-Kreinecker
Sabine
S
Berger
Walter
W
Lefranc
Florence
F
Kiss
Robert
R
D016375:Antisense Elements (Genetics); D015153:Blotting, Western; D001932:Brain Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D004721:Endoplasmic Reticulum / Q000378:metabolism; D037483:Galectin 1 / Q000235:genetics* / Q000502:physiology*; D020868:Gene Silencing; D023281:Genomics; D005909:Glioblastoma / Q000378:metabolism*; D006801:Humans; D039001:Integrin alpha Chains / Q000096:biosynthesis; D019012:Integrin beta1 / Q000096:biosynthesis* / Q000235:genetics*; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis; D051744:Protein Kinase C-epsilon / Q000502:physiology*; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014746:Vimentin / Q000502:physiology*
D016375:Antisense Elements (Genetics); D037483:Galectin 1; D039001:Integrin alpha Chains; D019012:Integrin beta1; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D014746:Vimentin; C084613:integrin alpha9; D051744:Protein Kinase C-epsilon